1. Technical Field
The disclosure relates generally to wireless communications, and more particularly to an apparatus and method for determining the location of a repeater.
2. Description of the Related Art
Wireless communication systems incorporate the use of repeaters to extend the service area of a base station. Repeaters extend the range of the base station by amplifying and re-transmitting wireless signals sent between a mobile subscriber and a base station.
Although, certain difficulties arise when the mobile subscriber is communicating with the base station via a repeater. In particular, the use of a repeater compromises the ability of a wireless communication system to determine the location of a mobile subscriber. This is due to the fact that signals passing through the repeater are subject to delays that are not present in signals that are transmitted directly from a mobile subscriber to the base station.
Because repeaters are deployed without a means for allowing a receiver to determine whether the signal was transmitted directly from a base station or through the repeater, a position location system using position location methods based upon triangulation or trilateration is not able to determine the location of the receiver. This inability to determine whether a received signal has passed through a repeater further compromises other position location technologies, such as hybrid wireless assisted Global Positioning Systems (GPS).
For example, a hybrid wireless assisted GPS system uses a combination of information from at least one satellite and at least one terrestrial transmission station, such as a base station of a wireless cellular communications system. Hybrid systems also use assistance data containing the fixed locations of base stations for determining the location of a mobile subscriber receiving signals from the base station. The mobile station determines the distance (or relative distance, in some cases) between itself and a base station from which the mobile station is receiving signals. The mobile station does this by determining the time at which the signal from the base station was received. This time may be either the absolute time of arrival or a relative time of arrival taken with respect to other signals received from other sources. Such other sources may be either terrestrial or satellite, for example. Thus, the location of the mobile subscriber is compromised if the propagation delay caused by a repeater is not taken into account.
The propagation delay can be overcome if the location of the repeater is known and can be taken into account during location determination. A method of automatically determining the location of a repeater during or after deployment will meet this need.